Pressurised Coolant tank

[patzer]

Hi All,

I've been out of commission for about a month, nothing serious but now I'm back to pester you again.

I got my Passat 1.9 tdi 130 serviced recently at my local VW ******* and one of the problems was that I was loosing a lot of coolant and the coolant reservoir was becoming pressurised as the level dropped. I'm not sure if it’s a vacuum or an over pressure but as soon as I open the lid there is a large hiss and the fluid level rises dramatically.

Anyhow, I had the T/B done and the water pump etc. I thought that the rad was leaking but when it was inspected I was told that it was fine and that it turned out that it was the old water pump that had a dodgy seal.

Happy with that (I didn't have to fork out for a new rad) I decided to wait and see.

Unfortunately the problem is still there although it doesn't appear to be as bad as before.

The garage did tell me that there could be a problem and that the engine could be taking in coolant during the induction stroke.

This worries me as this would indicate that the head gasket is shot.

There is a very slight oily residue on the surface of the coolant but there is no gunk/foam in the engine oil.

If anyone has any ideas I would be very grateful.

Thanks

Pat

[STEWY L]

oil cooler,common problem.
as far as "a large hiss and the fluid level rising" when you remove the cap,well any system does that.it's pressurised under normal circumstances to between 7-14psi. as soon as you remove the cap it then drops to atmospheric and the coolant boils.
take care,
stewy.